JP6448701B2 - Confocal endoscope system - Google Patents

Description

  The present invention relates to a scanning probe that scans a subject.

  There is known a scanning image system that images a signal obtained by periodically scanning a subject (such as a living tissue) in a body cavity (for example, Patent Document 1). This type of scanning image system includes a scanning probe having a single mode optical fiber, a biaxial (XY axis) actuator, and a uniaxial (Z axis) actuator. Inside the scanning probe, the optical fiber is held in a cantilever shape by a biaxial actuator at the base end. The biaxial actuator modulates and amplifies the amplitude of vibration while vibrating the tip of the optical fiber two-dimensionally at a predetermined frequency (for example, two-dimensionally resonating at the natural frequency), thereby Is spirally moved on a predetermined surface. On the other hand, the uniaxial actuator moves the optical fiber in the depth direction of the subject perpendicular to the predetermined plane according to the operation of the operator. By combining the biaxial movement of the optical fiber by the biaxial actuator and the uniaxial movement of the optical fiber by the uniaxial actuator, the scanning light transmitted from the light source by the optical fiber scans the subject in a spiral shape three-dimensionally. To do. The scanning image system detects return light from a subject scanned with scanning light, generates an image of a scanned area from the detected return light, and displays the generated image on a display screen of a monitor.

JP 2004-321792 A

  In order to reduce the burden on the patient during insertion into the body cavity, the scanning probe exemplified in Patent Document 1 is constantly required to have a reduced diameter design. However, the scanning probe described in Patent Document 1 drives the optical fiber in the depth direction, such as a nitinol wire and position sensor for controlling the scanning in the depth direction, and a spring that acts against the contraction of the nitinol wire. Mechanisms for control are arranged in the radial direction. Therefore, the configuration is not suitable for reducing the diameter of the tip of the scanning probe.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a scanning probe having a configuration suitable for narrowing design.

  The scanning probe according to the present embodiment includes an optical fiber, a movable cylinder portion that accommodates and holds the optical fiber, an accommodation cylinder portion that accommodates the movable cylinder portion, a proximal end surface of the movable cylinder portion, and an inner wall surface of the accommodation cylinder portion. And a shape memory alloy that slides the movable cylinder part in the axial direction integrally with the optical fiber in the accommodation cylinder part by expanding and contracting in the axial direction by energization, and the outer peripheral surface of the movable cylinder part It is arrange | positioned between the internal peripheral surfaces of a cylinder part, and is provided with the urging | biasing spring which urges | biases a movable cylinder part to an axial direction and the direction opposite to a shape memory alloy.

  According to this embodiment, the shape memory alloy and the biasing spring for controlling the driving of the optical fiber in the depth direction are arranged at positions shifted in the axial direction. Thereby, since the number of parts arranged in the radial direction is reduced, the scanning probe is reduced in diameter.

  The movable cylinder portion accommodates and holds the optical fiber, and may be configured to include an inner cylinder in which a long hole in the axial direction is formed on the peripheral surface. Moreover, the structure provided with a fixed cylinder part may be sufficient as an accommodation cylinder part. Specifically, the fixed cylinder part is formed with a screw hole at a position corresponding to the elongated hole, and the screw is inserted into a region where the elongated hole of the inner cylinder inserted into the fixed cylinder part and the screw hole overlap. By being stopped, the inner cylinder is slidably held in the axial direction within a range where the shaft portion of the screw fixed to the screw hole and each of the pair of end faces in the longitudinal direction of the elongated hole contact each other.

  The accommodation cylinder part may be configured to include an outer cylinder that accommodates the fixed cylinder part and the movable cylinder part. In this configuration, the biasing spring is disposed between the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder.

  The scanning probe may be provided with a limit sensor that is disposed between the base end surface of the movable cylinder portion and the inner wall surface of the housing cylinder portion and detects contact with the base end surface. For example, the limit sensor comes into contact with the base end surface of the movable cylinder portion before the screw comes into contact with the end surface in the longitudinal direction of the long hole.

  The movable cylinder part may be configured to include a first substrate bonded and fixed to the proximal end of the inner cylinder. Moreover, the structure provided with the 2nd board | substrate bonded and fixed to the position facing a 1st board | substrate may be sufficient as an accommodation cylinder part. In this configuration, the shape memory alloy has one end connected to the first substrate and the other end connected to the second substrate.

  The scanning probe has a flexible substrate that has one end connected to the first substrate and the other end connected to the second substrate, and bends as the distance between the first substrate and the second substrate decreases. It is good. In this configuration, a relief hole for the bent flexible substrate is formed in the fixed cylinder portion.

  According to the scanning probe of the present embodiment, a scanning probe having a configuration suitable for a narrow diameter design is provided.

It is an external appearance perspective view which shows the external appearance of the front-end | tip part of the scanning confocal probe of embodiment of this invention. It is an internal structure figure (perspective view) which shows the internal structure of the front-end | tip part of the scanning confocal probe of embodiment of this invention. It is sectional drawing of the front-end | tip part of the scanning confocal probe of embodiment of this invention. It is a figure which shows the inner cylinder and fixed cylinder with which the scanning confocal probe of embodiment of this invention is equipped.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following, a scanning confocal probe will be described as an embodiment of the present invention.

  The scanning confocal probe 1 of this embodiment is a medical instrument that constitutes a scanning confocal endoscope system designed by applying the principle of a confocal microscope, such as a tomographic image of a living tissue in a body cavity. Is preferably configured for observing the image with high magnification and high resolution. Information on the living tissue acquired by the scanning confocal probe 1 is transmitted to the video processor and processed by the video processor so that it can be displayed on the monitor. For the sake of convenience, the illustration of the components other than the scanning confocal probe 1 constituting the scanning confocal endoscope system, such as a video processor and a monitor, is omitted.

  FIG. 1 is an external perspective view showing the external appearance of the distal end portion of the scanning confocal probe 1 of the present embodiment. As shown in FIG. 1, the scanning confocal probe 1 includes a cover glass portion 11. An outer cylinder 12 is attached to the base end of the cover glass portion 11. A flexible tube 13 is attached to the proximal end of the outer cylinder 12.

  FIG. 2 is a perspective view in a state where the cover glass portion 11, the outer cylinder 12 and the flexible tube 13 are removed, and shows the internal structure of the distal end portion of the scanning confocal probe 1. 3A and 3C are side cross-sectional views showing a cross section that appears when the scanning confocal probe 1 is cut along the plane A in FIG. FIG.3 (b) is a figure which shows the BB cross section of Fig.3 (a).

  As shown in FIG. 3A, the scanning confocal probe 1 includes an inner cylinder 21 accommodated in the outer cylinder 12. A drive cylinder 22 that is also housed in the outer cylinder 12 is connected to the inner cylinder 21 by press-fitting or bonding to the middle of the outer peripheral surface of the inner cylinder 21. As shown in FIG. 2, an objective lens portion 23 is attached to the tip of the drive cylinder 22 by adhesion or the like. The objective lens unit 23 is accommodated in the cover glass unit 11 and the outer cylinder 12.

  As shown in FIG. 3A, an optical fiber 24 coated and protected by a Teflon tube (Teflon: registered trademark), a PEEK tube (PEEK: registered trademark), or the like is accommodated in the flexible tube 13. ing. The proximal end of the optical fiber 24 is coupled to a light source unit (not shown). The distal end portion of the optical fiber 24 (hereinafter referred to as “optical fiber distal end portion 24 a”) is accommodated and held in the inner cylinder 21. A biaxial actuator (not shown) is attached by bonding or the like near the base of the optical fiber tip 24a. The biaxial actuator is a piezoelectric actuator, and resonates the optical fiber tip portion 24a in two directions (XY directions) orthogonal to the axial direction of the inner cylinder 21 (also the axial direction of the scanning confocal probe 1). Exercise. One end of a signal line for transmitting a drive signal is soldered to each electrode formed on the piezoelectric element included in the biaxial actuator. In the scanning confocal probe 1, a plurality of signal lines 25 connected to various electronic components such as a signal line for driving a piezoelectric element are wired over almost the entire length.

  FIG. 4A shows a perspective view of the inner cylinder 21 alone. As shown in FIG. 4A, the proximal end side of the inner cylinder 21 has a stepped shape. Further, the base end surface of the inner cylinder 21 is open. As shown in FIG. 3A, a PCB (Printed Circuit Board) 26 is bonded to the proximal end opening of the inner cylinder 21. The proximal end opening of the inner cylinder 21 is closed by an adhesively fixed PCB 26. The PCB 26 is an MID substrate in which a pattern is provided on the surface of a molded product such as resin or ceramics in order to secure an area necessary for pattern design.

  As shown in FIG. 3A, a fixed cylinder 27 is accommodated in the outer cylinder 12, and is fixed by adhesion or the like. Here, FIG. 4B shows a state where the inner cylinder 21 and the fixed cylinder 27 are assembled. As shown in FIG. 4B, the inner cylinder 21 (near the base end opening including the stepped shape) is inserted into the fixed cylinder 27. A long hole 21 a that is long in the axial direction is formed on the peripheral surface of the inner cylinder 21. A screw hole 27 a is formed on the peripheral surface of the fixed cylinder 27.

  When the inner cylinder 21 is inserted into the fixed cylinder 27, as shown in FIG. 4B, a part of the long hole 21a overlaps the screw hole 27a. As shown in FIG. 4C, the shaft portion of the screw 28 is inserted into the overlapping region (the region penetrating the peripheral surface of the inner tube 21 and the peripheral surface of the fixed tube 27), and the screw 28 is inserted into the screw hole 27a. Screwed in. As shown in FIG. 3B, the diameter of the screw hole 27 a and the width of the long hole 21 a (length in the short direction) are substantially the same as the shaft diameter of the screw 28. Therefore, when the inner cylinder 21 and the fixed cylinder 27 are rotated relative to each other around the axis, the shaft portion of the screw 28 and the end surface of the screw hole 27a or the end surface of the long hole 21a in the short direction contact each other. Thus, the relative rotation around the axis of the inner cylinder 21 and the fixed cylinder 27 is substantially caused by the shaft portion of the screw 28 and the end surface of the screw hole 27a or the end surface of the elongated hole 21a in the short direction. Are regulated.

  The outer peripheral surface of the inner cylinder 21 and the inner peripheral surface of the fixed cylinder 27 are in a clearance fit relationship. The fixed cylinder 27 holds the inner cylinder 21 in a clearance fit relationship so as to be slidable in the axial direction (see FIGS. 4C and 4D). When the inner cylinder 21 slides in the axial direction with respect to the fixed cylinder 27, the elongated hole 21a moves in the axial direction (longitudinal direction of the elongated hole 21a) with respect to the screw 28 screwed into the screw hole 27a. In other words, the screw 28 moves in the axial direction within the elongated hole 21a.

  As described above, the width (length in the short direction) of the long hole 21a and the shaft diameter of the screw 28 are substantially the same. Therefore, the long hole 21 a functions as a guide when the inner cylinder 21 is slid in the axial direction with respect to the fixed cylinder 27.

  As shown in FIG. 3A, the PCB 29 is bonded to the fixed cylinder 27 so as to face the PCB 26. The PCB 29 is also an MID substrate like the PCB 26. In a space between the PCB 26 and the PCB 29, a shape memory alloy (Nitinol wire) 30, a position sensor 31, a limit sensor 32, and an FPC (Flexible Printed Circuits) 33 are installed. One end of the shape memory alloy 30, the position sensor 31 and the FPC 33 is connected to the PCB 26, and the other end is connected to the PCB 29.

  As shown in FIG. 3A, a bias spring 34 is accommodated in a cylindrical space defined by the outer peripheral surface of the inner cylinder 21 and the inner peripheral surface of the outer cylinder 12. One end of the bias spring 34 is in contact with the end surface 22 a of the drive cylinder 22, and the other end is in contact with the end surface 27 b of the fixed cylinder 27. The bias spring 34 is initially compressed and clamped between the end surface 22a of the drive cylinder 22 and the end surface 27b of the fixed cylinder 27 in the axial direction (Z direction) from the natural length.

  The shape memory alloy 30 has a long rod shape in the axial direction, and deforms when an external force is applied at room temperature, and has a property of restoring to a predetermined shape by a shape memory effect when heated to a certain temperature or higher. ing. The shape memory alloy 30 is designed such that the restoring force due to the shape memory effect is larger than the restoring force of the bias spring 34. The shape memory alloy 30 is energized and heated by a driver (not shown) to control the amount of expansion and contraction.

  The shape memory alloy 30 advances and retracts the movable cylinder part in the axial direction within the accommodation cylinder part according to the amount of expansion and contraction. Here, the movable cylinder part is an element that moves in the axial direction according to the expansion and contraction of the shape memory alloy 30, and includes an inner cylinder 21, a drive cylinder 22, an objective lens part 23, an optical fiber 24 (including an optical fiber tip portion 24a). And PCB 26. The housing cylinder part is an element that does not move with respect to the expansion and contraction of the shape memory alloy 30, and includes the cover glass part 11, the outer cylinder 12, the flexible tube 13, the fixed cylinder 27, and the PCB 29. Specifically, the shape memory alloy 30 is heated and contracts (restores) in the axial direction, thereby retracting the movable cylindrical portion backward (in the axial direction) within the accommodating cylindrical portion. The shape memory alloy 30 is also stretched in the axial direction by the bias spring 34 as the restoring force due to the shape memory effect decreases as the slow cooling progresses. The shape memory alloy 30 is extended in the axial direction, thereby pushing the movable cylindrical portion forward (axial direction) within the accommodating cylindrical portion.

  The movable range of the movable cylinder within the housing cylinder is mechanically determined by each of the shaft portion of the screw 28 screwed into the screw hole 27a of the fixed cylinder 27 and the pair of end surfaces 21b in the longitudinal direction of the long hole 21a. It is regulated within the range that hits. However, if energization to the shape memory alloy 30 is continued in a state where the shaft portion of the screw 28 and the end face 21b of the elongated hole 21a are in contact, the shape memory alloy 30 may be disconnected. Therefore, in the present embodiment, the moving range of the movable cylinder part in the accommodation cylinder part is electrically controlled. Specifically, the scanning confocal probe 1 is configured such that the shaft portion of the screw 28 and the end surface 21b of the slot 21a are retracted when the movable cylinder portion is retracted in the accommodating cylinder portion by energizing and contracting the shape memory alloy 30. The limit sensor 32 comes into contact with the PCB 26 immediately before hitting. The contact detection signal from the limit sensor 32 is transmitted to the video processor. The video processor controls the driver based on the detection signal to switch off the energization to the shape memory alloy 30 or to intermittent energization. Thereby, disconnection of the shape memory alloy 30 due to excessive energization is avoided.

  The bias spring 34 is expanded and contracted in the axial direction in accordance with the movement of the movable cylinder part in the accommodation cylinder part (more specifically, the movement of the end surface 22a of the drive cylinder 22 with respect to the end surface 27b of the fixed cylinder 27). Here, the bias spring 34 surrounds the outer peripheral surface of the inner cylinder 21 and is surrounded by the inner peripheral surface of the outer cylinder 12. The bias spring 34 is supported by the outer peripheral surface of the inner cylinder 21 on the inner diameter side and supported by the inner peripheral surface of the outer cylinder 12 on the inner diameter side, so that the bias spring 34 is smoothly expanded and contracted in the axial direction without falling down in the axial direction. .

  As shown in FIG. 3A and FIG. 4B, a peripheral surface opening 27 c is formed on the peripheral surface of the fixed cylinder 27. The peripheral surface opening 27 c is an opening necessary for performing an operation of mounting various components such as the shape memory alloy 30 and the position sensor 31 in the fixed cylinder 27. Further, the FPC 33 bends as the distance between the PCB 26 and the PCB 29 becomes narrower. As shown in FIG. 3C, the peripheral opening 27c also functions as a relief hole for allowing the bent FPC 33 to escape.

  The above is the description of the exemplary embodiments of the present invention. Embodiments of the present invention are not limited to those described above, and various modifications are possible within the scope of the technical idea of the present invention. For example, the embodiment of the present application also includes contents appropriately combined with examples and the like clearly shown in the specification or obvious examples.

DESCRIPTION OF SYMBOLS 1 Scanning confocal probe 11 Cover glass part 12 Outer cylinder 13 Flexible tube 21 Inner cylinder 21a Elongate hole 21b End face 22 (longitudinal direction of the elongate hole) Drive cylinder 22a End face 23 of drive cylinder Objective lens part 24 Light Fiber 24a Optical fiber tip 25 Signal line 26 PCB
27 Fixed cylinder 27a Screw hole 27b End face 27c (of fixed cylinder) Peripheral surface opening 28 (of fixed cylinder) Screw 29 PCB
30 Shape memory alloy 31 Position sensor 32 Limit sensor 33 FPC
34 Bias spring

Claims (3)

Optical fiber,
An inner housing for holding the optical fiber;
An outer housing portion for housing the inner housing portion;
One end is fixed to the inner housing portion and the other end is fixed to the outer housing portion, and the inner housing portion is integrated with the optical fiber in a predetermined axial direction within the outer housing portion by expanding and contracting by energization. A shape memory alloy to be moved;
A biasing spring that biases the inner housing portion in the predetermined axial direction and in a direction opposite to the shape memory alloy;
A confocal endoscope system comprising :
The inner housing portion is
Having an outer peripheral surface along the predetermined axial direction;
Containing and holding the optical fiber, and an inner tube having a long hole formed in a peripheral surface in the predetermined axial direction;
A first substrate adhesively fixed to the proximal end of the inner cylinder;
With
The outer housing portion is
An inner peripheral surface along the predetermined axial direction;
A fixed cylinder part into which the inner cylinder is inserted;
A second substrate bonded and fixed at a position facing the first substrate;
With
The fixed cylinder part is
A screw hole is formed at a position corresponding to the elongated hole, and a screw is inserted into a region where the elongated hole of the inner cylinder inserted into the fixed cylinder portion and the screw hole are overlapped to be screwed, The inner cylinder is slidably held in the predetermined axial direction within a range where the shaft portion of the screw fixed to the screw hole and each of the pair of end faces in the longitudinal direction of the elongated hole hit each other,
The biasing spring is
It is arranged at a position shifted in the predetermined axial direction with respect to the shape memory alloy, and is arranged in a first space which is a space between the outer peripheral surface of the inner housing portion and the inner peripheral surface of the outer housing portion. ,
The first space is
In the predetermined axial direction, it is a space located in front of the base end surface of the inner housing portion,
The shape memory alloy is
In the predetermined axial direction, the space is located behind the base end surface of the inner housing portion, and is the space between the inner wall surface of the outer housing portion and the base end surface facing the base end surface. Placed in the second space,
One end is connected to the first substrate, the other end is connected to the second substrate,
The confocal endoscope system further includes:
One end connected to the first substrate, the other end connected to the second substrate, and a flexible substrate that bends as the distance between the first substrate and the second substrate decreases.
With
A relief hole for the bent flexible substrate is formed in the fixed cylinder portion,
Confocal endoscope system. The outer housing portion is
An outer cylinder for accommodating the fixed cylinder part and the inner accommodating part,
The biasing spring is
It is disposed between the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder.
The confocal endoscope system according to claim 1 . A limit sensor that is disposed in the second space and detects contact with a base end surface of the inner housing portion;
The limit sensor is
The screw comes into contact with the proximal end surface before coming into contact with the longitudinal end surface of the elongated hole;
The confocal endoscope system according to claim 1 or 2 .

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